This invention relates to orthotic devices for limbs and more particularly to a joint for a brace that permits extension and flexion through an adjustable angle and also provides means for continuously adjustably fixing an abduction angle while being worn on the limb.
Davis et al. in U.S. Pat. No. 5,421,810 issued Jun. 6, 1995 teach a hinge having a continuously adjustable stop at one end of the extension-flexion rotation. They provide discontinuous means for adjustment of the fixed abduction angle that requires releasing the joint connection, moving the limb to the desired angle, and then tightening the connection. Using matching gear teeth limits the adjustment to discrete angles.
Williamson et al. in U.S. Pat. No. 5,368,552 issued Nov. 29, 1994 provide an excellent review of the art and disclose a ball and socket connection in the joint to allow another degree of rotation.
Borig et al. in U.S. Pat. No. 4,881,532 issued Nov. 21, 1989 disclose a joint in which there is free abduction motion through a limited angle.
When fitting a brace, especially a hip brace after surgery, the physician will often prescribe a fixed abduction angle to reduce stress on the joint, especially when sitting. When fabricating the brace, it is difficult to predict what the actual abduction angle will be until it is mounted on the body.
If it is not as prescribed, it must be removed, adjusted and mounted again. When the angle is to be changed for some clinical reason, the process must be repeated. When fitting the brace, it is often tempting to disregard small deviations from the required abduction angle. The same holds true for adjustments of the flexion/extension angular extremes. It would be useful to have a joint in which the fixed abduction angle could be continuously adjusted after the brace is mounted on the patient, and where adjustment could be easily made.